Electronic accumulator



Dec. 18, 1951 P. cRosMAN ELECTRONIC AccuMULA'roR Filed July 8, 1948 4 Sheets-Sheet 1 WM, ,QW

ATTORNEYS.

Dec. 18; 1951 Filed July 8, 1948 Ilz 2.

L.. P. cRosMAN ELECTRONIC ACCUMULAT'OR 4 Sheets-Sheet 2 INVENTOR. LoRpNG P. cRosMAN DCC 18, 1951 L.. P. cRosMAN 2,579,174

l ELECTRONIC ACCUMULATOR Filed July 8, 1948 4 Sheets-Sheet 5 JNVENToR. LORING P. cRosMAN @mf-UL.

ATTORNEYS.

Dec. 18, 1951 L. P. cRosMAN 2,579,174

` ELECTRONIC ACCUMULATOR l Filed July 8, 1948 4 Sheets-Sheet 4 1 1k 1: I 2 3 4 5 6 t7 8 9 INVENTOR. LOFUNG P. CROSMAN 'ATTORNEYS' Patented Dec. 18, 1951 ELECTRONIC ACCUMULATOR Loring P. Crosman, Darien, Conn., assignor to Remington Rand Inc., New York, N. Y., a corporation of Delaware Application July 8, 1948, Serial No. 37,652

4 Claims. (Cl. 235-92) This invention relates to an electronic accumulator and has particular reference to a system of electronic triodes which m-ay accumulate digit values in response to applied electrical pulses. While the invention is subj ect to a wide range of applications, it is especially suited for use in an electronic calculator and will be described in that application. Y

In order to reduce the number of tubes and circuits, two counters are employed to accumulate values from zero to nine; a radix-of-two counter and a radiX-of-iive counter. Each counter uses stabilized trigger circuits for the recording of Vdigit values. As used throughout the specification and claims, the term unbalanced trigger refers to a trigger stage comprising two electronic triodes with circuit components so adjusted that the circuit is stable only when one triode is conducting and the second tricde is non-conducting.

vApplying an actuating pulse to such a stage momentarily switches conductivity and generates a pulse, the duration of which depends upon the circuit constants. This type of circuit is also called a one-shot multivibrator and a flipop.I v

Electronic accumulators have been used in many applications where speed of recording is the dominant factor of design and operation. The first and most obvious design included ten stages for each denominational order, each stage representing a digit from zero to nine. Such a design required a large number of vacuum tubes and efforts have been made to reduce the number of stages and tubes by various circuit arrangements. One type of counter -uses only four stages, but the difficulties in decoding and reading out the accumulated values make this type of circuit difcult to handle. The present Lcircuit design requires six counter stages and is designed to facilitate the operations involving addition, subtraction, multiplication, and division.

It is an object of this invention, therefore, to provide an improved accumulator circuit which vavoids one or more of the disadvantages and limitations of prior art arrangements.

Another object of the invention is to provide an electronic accumulator which can be voperated by a series of electric pulses generated by a multivibrator.

Another object of the invention is to provide an electronic accumulator with a'radix-of-two counter and a radix-of-ve counter with an actuating circuit for directly entering digit values into either counter.

The invention comprises an accumulator for receiving and storing values from one to nine and comprises, a radiX-of-two counter for recording single' digit values received from a pulse generator, and aradix-of-ve counter for recording double digitvalues received from a pulse generator and from the -radix-of-two counter,

One of the features of the invention includes a double triode trigger circuit which is actuated .by a single pulse when a one is entered into the accumulator or when any other odd digit is recorded.

Another feature of the invention includes a series of five double triode trigger circuits which are actuated Whenever an even digit is recorded by the accumulator.

For a better understanding of the present invention, together with other and further objects thereof, reference is made to the following description taken in connection with the accompanying drawings.

Fig. l is a block diagram showing how the various stages are connected.

Fig. V2 is a schematic diagram of connections and shows the essential components of the pulse generating system.

Fig. 3 is a schematic diagram of connections and shows the components of the accumulator, the keyboard and the lamp digit indicators.

Fig. 4 is a diagram which indicates how Figs. 2 and 3 are to be combined to show the complete wiring diagram of the system.

Fig. 5 is a series of graphs showing the character of the pulses produced invarious parts of the circuit.

Referring now to Fig. 1, the entire system will be generally described,.neglecting at present the detailed features of the invention. A starting key I0 is connected to a preliminary pulse generator H which generates a sharp pulse (Fig. 5-a) when the key contacts are made. Next, an unbalanced trigger stage l2 transforms the sharp pulse into a broad flat-topped pulse (Fig. 5-ZJ) of the same magnitude and duration as the pulses which later are generated by the multivibrator. The unbalanced trigger stage l2 also controls an electronic switching stage i3' which turns on a multivibrator oscillator l. The switching stage i3 is also operated, but in a reverse direction, by a frequency divider stage i5 to turn the multivibrator off.

The output of the multivibrator, in this eX- ample equal to four pulses (Fig. 5-d) is fed to a frequency divider l5 which vreduces the four pulses to two (Fig. 5e), and these two pulses are fed .to a second frequency divider i6 which reduces the number of pulses to one (Fig. 5-f).

The output of this divider is fed back over con-V portions ofthe circuit, single, double, and quad-v ruple pulse trains Which may be used singly or in combination to `produce sharp pulse trains (Figs. -z' to 5-m) to count from one to nine. To this end, four buffer stages 2D, 2l, 22, and 21 are provided, also a mixer stage 23, and an inverter 2s.

Fig. 5 shows a number of' pulse forms as they appear in different parts of the circuit, arranged in their proper phase relation. Curve 5i shows the wave-form of the sharp pulses from the multivibrator after they have been transmitted through buffer stages 2e and 21. The output from the first frequency divider i5 is shown at 5e, and this wave form is changed to 54a after passing through the left-hand part of buffer stage 21. The result is a double pulse with points occurring at times t3 and t7. The output of the second frequency divider I5 is a single pulse 5-f. When this is fed to the left-hand side of buifer stage 21, a single sharp pulse results (5-1), the point occurring at time t5. The above described pulses may be combined to form a triple pulse 5-4' by sending the two lwave trains (5-e and f) through the mixing stage 23.

Referring again to Fig. l, a keyboard '25 contains ten manually settable switches which designate and control the number and value of the pulses transmitted to an accumulator or counter circuit 26. If the number to be transmitted is even, the pulses are delivered to the left-hand side of amplier stage 21 (shown in detail in Fig.

3), and then transmitted to all the radiX-of-.iive stages in the accumulator. If the number to be recorded is one, the keyboard switch delivers a single pulse to the` rightfhand side of stage 2 where it is amplied and sent to stage 28, the

radiX-of-two counter. If the number to be recorded is odd and greater than one, a single pulse is sent to the right-hand side of stage 21 while the remaining pulses, representing an even value, are sent through the left-hand side of stage 21 to the radiX-of-ive stages in counter 25. The output of the counter stages 25 and 28 may be used by any suitable calculator circuit, storage device, or read-out mechanism. In order to simplify the circuit, the present system is shown operating a bank of ten lamp indicators 35.

Having now described the general system of pulse generation, reference is made to Figs. 2 and 3 where the detailed schematic wiring diagram is shown. The detailed description of pulse generation is set forth in patent application, Se-

ductor 33 connects to keys 4 and 5, and conductors 34 and 3 5 connectv to key groups 6, '1 and 8, 9 respectively. YAll the double valued pulses are connected by the keyboard switches to a conduc tor 31 which runs to the control electrode of the left-hand side of amplifier stage 21.

Stage 21 is a limiter stage and is normally adjusted with the control electrodes biased below the conducting value so that only positive pulses will cause conduction in the anode circuit. A negative pulse ,has no effect on the conductivity. The odd or right-hand section of stage 21 has its output connected to trigger stage A-i which is the radix-of-two counter. It is normally conducting on the left-hand side. A Single positive pulse transmitted over conductor 36 produces a negative pulse in anode conductor 38 and actu!- ates stage A-l, transferring the Vconducting path within the tube to the rightfhand side. This lowers the potential of conductors QD and 4l and delivers a negative pulse tothe control electrode of tube 52. Tube 42 is a buffer amplifier with its control electrode biased below the potential for anode conductance, hence a negative pulse applied to this tube causes no effect. If a second pulse is applied from stage 21 over conductor 33 to actuate stage Aal, the conductance will 'be shifted back to the left-hand side and a positive pulse will be sent over conductor di to tube #32. This pulse will be transmitted, since it is posi-.- tive and increases the potential of the control electrode of tube 42. The anode current surge sends a negative pulse over conductor 4.3 to com ductor 44 which connects with all the radlXeof-s five stages and actuates any of them that are cond ducting on the right-hand side. The ve trigger stages Which make up the radix- .offve counter represent the even numbered digits in the decimal or denary system and are designated A-S, AJ,

f A-i, A-6, and A-B to indicate the values handled rial No. 18,782, filed April 3, 1948, now Patent No.

2,512,861, issued June 2*'1, 1950. The net result of the pulse generating system is to provide a single pulse at time t1 (Fig. 5-b) on conductor 31; also a single pulse having double value at time t5 (Fig. 5.f) on conductor 32; also a double pulse representing the value of four at times t3 and t7 (Fig. 5-e) on conductor 33; also a triple pulse representing the value cf six having pulse rise points at times t3, t5, and tf1 (Fig. 5-.h) on conductor 34; and a quadruple pulse representing the value of eight having pulse rise points at times t2, t4, te, and t (Fig. lied) on conductor 35.

All the conductors, 3| to 35, for the transmission of counting pulses are connected to one or. more of the nine keys in keyboard 25. The conductor Si which transmits a single pulse at time t1 is connected to all the odd designated keys and z by them. The A-il has part of its output con.- nected to the left-hand control electrode of the A-2 stage; the output of the A-2 stage is con@ nected to theletfhand control electrode of the A-li stage; the A- andA- stages being similarly connected, and the A4 stage output connected back to the control electrode of the A- stage and also connected to the carry circuitwhich carries to the next higher denominational order. Y

Each of the iive stages, A..i to A18, has the Gut.- put of its left-hand section connected to one` tera minal of two neon indicator lamps in the lamp indicator assembly 32. The other terminals of the lamps are connected by conductors 45 and l5 to rectifying elements 41 and 48 and then to the two anodes in stage A.I. A detailed exfplanation of the kneon lamp indicator circuit may be found in U. S. patent application, Serial f` No. 33,947, sled June 19, 1948, now Pai-.ent No.

2,563,102, issued August 7, 1951'.

A zeroize or normalizing key 5i) is included m series with one of the cathode conductors .5| .so that its opening will insert a resistance 52 in series with all the cathodes that normally should be non-conducting. The zeroizing action also extends to the pulse generator stages and normalizes any trigger stage in that circuit that may not have vbeen left in the normal condition.

Operation side and A- is conducting on the right. The cross-hatched lines on the tube drawings in Fig. 3 indicate the conductive condition. Neon indicator lamp 53 (designating zero) is lighted because one of its conductors 54 leads to the anode in stage A-D which is at high potential and the other conductor 46 leads through rectifier 48 to the anode of stage A-I which is at low potential.

Now assume that the number'4 key in the keyboard be depressed, joining conductors 33 and 31; Then the start key I0 is closed, and condenser' 55 is discharged thereby providing voltage yfor the ionization of neon tube 56 and impressing a voltage rise on condenser 51. This action' impresses a sharp negative pulse on the anode of the tube in stage the form and timing of which are shown in Fig. -a. This pulse is transmitted over conductor I9 to the unbalanced trigger stage,y I2 which produces a iiattopped Wave (Fig. 5-b) which is transmitted over conductors 60 and 6| to the control electrode of switching stage I3 and buier amplifier stage 2|.

The application of a pulse to stage I3 turns on the multivibrator by increasing the potential son control electrode 62 to a value that permits oscillation. The output of the multivibrator is transmitted over conductor 63 to the first fre quency divider stage I5 where the four pulses generated by the multivibrator are transformed into two pulses (Fig. 5-e) and then applied to the leftha-nd side of buffer amplifier 22. The output of amplifier 22 is carried by conductor 33 to the key 4 which is closed, then over conductor 31 tov A-Il stage since it is the only stage conductingY on the right-hand side. The application of the pulse changes the anode conduction to the lefthandside and in making the transfer, a negative lpulse is sent over conductor 64 to the left-hand control electrode of the A-2 stage and transfers its conductance to the right-hand side.

When the second negative pulse from stage 21 is transmitted over conductor 44, it actuates only the A-2 stage since at this time it is the only stage that is conducting on the right. The conductance of the A-2 stage will be transferred to the left-hand side, and, in so doing, apulse will be sent over conductor 65 and actuate the f.6i-4 stage by transferring the conductance to the right-hand side. Hence, at the end of the double negative pulse, only the A-4 `stage is conducting on the right. This condition causes thenumber 4 neon indicator lamp to be lighted since one of its conductors 66 is' connectedto the left-hand anode of stage A-4 which is now at high potential while the other conductor 46 leads to the lefthand anode of stage A| which is at low potential.

The .above described action is finished a small interval of time before the end of a pulsing cycle since the second activating pulse occurs at time t7 as shown on Fig. 5-k. The multivibrator continues with its fourth pulse and is finally turned oi by the action ofr the second frequency divider stage'l, which sends a pulse at time te over conductor 61 to the right-hand control electrode in stage I3 which reduces the potential on conductor 68 and stops the multivibrator action.

After the finish of the pulsing cycle, the counter stages and the indicator lamps v3|! remain in their operated condition `:sc'that they may be ready for additional pulses or until the result may be copied or transferred to another part of the calculator system;

In order to illustrate the action of thefA-I stage, let it be assumed .that the counter stages are left with the digit value of four recorded therein' and the 5 key depressed. Then, when the start key I0 is closed, the same train of pulses is `started as was described above. The same two pulses will be transmitted over conductor 33, through the bottom contacts of the number ve key, and thence over conductor 31 'to the lefthand side of stage 21. But, in addition, and before the transmittal of the double pulse (Fig. 5-k) a single pulse (Fig. 5 -b) is transmitted from the unbalanced trigger stage I2 over conductor 6 I, through amplifier stage 2 I, over conductor 3| to the top contacts of the ve key, thence overY conductor 3,6 to the right-hand side of stage 21. The single positive pulse transmitted to stage 21 is sent overconductor 38 as a negative pulse to stage A-I. and transfers the anode vconductance to the right-hand side. When the right hand anode is made conducting, a negative pulse is sent over conductor 4| to tube 42. This tube, however. has its control electrode biased to the cut-off point and the negative pulse has no eiect.

The two pulses transmitted through the bottom contacts of keynumber '5 to the left-hand side of amplifier stage 21 are applied to conductor 44. and by actuating two stages, as described above, advance the actuated stages by two to the A-B position.

The accumulator has now an actuated A- stage and an actuated A| stage and has thereby recorded the value nina v Let it now be assumed thatv a one is to be added to the accumulator. The one key in the keyboard is depressed, and conductors 36 and 3| 'are connected. When the start key I0 is depressed, a single positive pulse is sent over conductor 36 to the right-hand side of stage 21, which in turn sends a negative pulse over conductor 38 to actuate stage A-l. This time the conductance is shifted from the right-hand side to the left, and a positive pulse is sent over conductor 4| to tube 42. This time the pulse is transmitted and appears as a negative pulse on conductors y43 and `44, applied to all the righthand control electrodes of the radix-of-five counter. The `only stage .which is conducting on the rightl side is the A-8 stage, and it is the only one actuated. Conductanceis shifted to the left-hand side, and a negative pulse is sent out from the left-hand anode circuit. The pulse is transmitted by conductor 10 to the left-hand control electrode of stage A-il which is. thereby actuated, and the conductance is returned -to the right-hand anode, its normal position. The voltage pulse generated bythe A-8 actuation is also transmitted over a carry conductor 1I, which sends a pulse vto a. storage trigger` stage (not shown) associated with the next higher denominational order. A shortinterval of time after the end of the accumulator cycle, the carry value is applied to the next radix-of-two counter.

All the stages are now in their original or normalized condition, except the next higher order accumulator which has recorded afone. The illustrated accumulator has recorded a 4, a 5," and a 1 in additive relation, and the ref sult is a 10. It will be obvious how other digit This'pulseV actuates the A-| stage` 1' values are recorded.' Allv even valued members are recorded by transmitting a number of: pulses to. the. radix-of-ve counter; the number of pulses being equal to half the number tov be re,- corded. All odd numbers are recorded by actuation of the radix-of-two counter, andthe recording of one less than the desired odd number in the` radix-of-ve counter.

Actuating pulses for, recording two. and four are illustrated in Figss'r-l and 5-k by single and double` negative pulses and are obtained from frequency dividerv stages, i6 and I5 and shaped byy the, diierentiating action of amplifier stage 27:. shown. in Fig. -1' and are obtained from the multivibrator output acting through stages 2G Actuating pulses for recording eight arel and 21. Actuating pulses for recording six are Y shown in Fig. 5-7 and are obtained from mixer stage 23` by the addition of a singlepulse and a double pulse. An inverter stage 24 '(Figg-h) and the right-hand side ofl buier amplifier 22 are employed to obtain the proper output. and po-f larity. From the above description, it will be evident that the invention may be used to accumuiate, digit values by using a radix-of-two counter and a. radix-of-ve counter in combination with.

apulse generating system especially suited to this combination.l

While there have been described and illustrated. Specificembodiments. of the invention, it

will be obvio-us that various changes and modicationsmay be made therein without. departing storing digit values from. zero to nine. comprising'. a radix-of-two. counter which includes a double-triode trigger stage and a rst input circuit for receivingfoperating pulses; a pulsegenerator coupled to. the rst input circuit for registering'single digit: values during one part of a counting cycle; a radix-of-five counter which includes ve double-triode trigger stages, each of which is assigned an even digit value, and a second input circuit for receiving operating pulses; a pulse generator coupled to the second input circuit, for registering double digit values during a second part of the counting cycle; a carry circuit, for transferring a carry pulse from .the radix-of-two'counter-to the second input circuit when the radix-of-two counter progresses yfrom. a count of one to a count of zero; and a second carry circuit for transferringv a carry pulse from the radix-of-ve counter to the radixofi-two counter in the next higher denominational order when the radiX-of-iive counter progresses from a count of nine to a count of zero.

4. Anlelectronic accumulator for receiving and storing digit values from zero to nine comprising,

a radix-of-two. counter which includes a doubletriode trigger stage and a first input circuit-for `receiving operating pulses; a pulse generator coupled to the first input circuit for registering single digit` values during one part of a countfve' double-triode trigger stages, each of which Vis assigned anv evendigit value, and a second infrom the. field of the invention which should be limited only by the scope of the appended claims.

What is claimed is:

l.v An electronic accumulator for receiving and storing digit values from zero to nine comprising, a radix-of-two counter which includes a doubletriode trigger stage and a first input circuit for receiving operating? pulses, apulse generator coupled to the first input circuit for registering single digit values during one part of a counting cycle, a

radix-of-iive counter which includes five double-V triode trigger stages and a secondinput circuit for receiving operating pulses, a pulse generator.

single digitv values during one part of a counting cycle; a radix-o'f-ve counter which includes ing cycle; a, radix-of-ve counter which includes put circuit which is connected to all of said radix- 1 of-five trigger stages in parallel arrangement for lreceiving operating pulses;

a pulse generator coupled to the second input circuit for registering double digit values` during a second part of the. counting cycle; a carry circuit for transferring a carry pulse, from the radx-of-two counter to the second input circuit when the radix-oitwo counter progresses from a count of one to a count of zero; and a second carry circuit for transferring a carry pulse from the radix-of-ve counter to the radix-of-two counter Yin the next higher denominational order when theradix-ofvecoun'ter progresses from a count of nine to a count Vof zero; Y

LORING P. CROSMAN.

` REFERENCES CITED k Thev following references are of record in the file of thispatentz- Y UNITED STATES PATENTS Number `.Name Date 2,401,621 vDesch et al. June 4, 1946 2,402,989 Dickinson July 2, 1946 .2,436,963 Grosdoii" Mar. 2, 1948 2,470,716 Overbeek f- May 17, 1949 FOREIGN PATENTS Number V Country Date 572,884 Great Britain Oct. 29, 1945 iive double-triode trigger stages, each of which is Y assigned an even digit value, and a second input circuit .for receiving operating pulses;A a pulse generator coupled to the second input circuit for registering do'uble digit values during a. second part of the counting cycle; and a carry circuit for transferring a carry pulse from the radix-oftwo counter to the second input circuit when the radix-of-two counter progressesV from a count of one to a count of zero.

3. An electronic accumulator for receiving and OTHER REFERENCES A Four-.Tube Counter Decade, Potter, Electronics, September 1944, pp. 11o-113, 353 and 360.

.'ElectronicCounters, Grosdoff, RCA Review. September 1946, p. 442. f

High-Speed N-Scale Counters, by T. K. Sharpless, Electronics,` March 1948; pp. 122-125. 

